印象派的主张 :光和色是绘画的生命，為了追色彩的变化必须一天到晚守着一件物体观察它，太阳不断地变化，物体是因光线投射在上面而有色并因光的变化而变化。而否定物体的本色，譬如树叶，一般是绿色的，但印象派的画家只承认它可能是绿色，却不一定是绿色它可能是紫色或橙色。

印象派的画家主张把画架搬到室外去以冷靜的头脑来观察和分析自然，似乎要发现自然界的秘密似的，即使是一堆稻草或是一滴露水，他们都要穷其究竟的画它，虽然在画面上它的地位只是极细致的枝节。

印象派的画家很多如莫纳(Monet)，马纳 (Manet)，毕沙罗(Pissarro)，雷诺亚(Renoir)，西斯莱(Sisley)，狄加(Degar)，特洛拉克(Toulouse-Lautrec )等等。在这许多画家当中狄加和特洛拉克的作品要算是生活气息最強的两个了。

The principles of Impressionism can be summarized as follows:

Light and Color as the Essence: Impressionist artists believed that light and color were the essence of painting. They emphasized capturing the immediate visual impression of a scene, particularly the effects of light and color on objects.

Continuous Observation: To capture the changing colors, Impressionist painters advocated continuous observation of a subject throughout the day. They believed that sunlight constantly changed, affecting the colors of objects. The artists would study and paint the same subject at different times to depict these variations.

Denial of Local Color: Impressionists rejected the idea of representing objects in their true, local colors. For example, if a tree leaf is traditionally considered green, an Impressionist painter would acknowledge that it could be green but would not limit it to that color. The leaf might be depicted as purple or orange, depending on the changing light conditions.

Outdoor Painting (En Plein Air): Impressionist painters preferred to paint outdoors (en plein air) to observe and analyze nature with a calm and analytical mind. They aimed to discover the secrets of the natural world. Even seemingly mundane subjects like straw or a dewdrop were meticulously painted to explore their intricacies, though they might appear as subtle details in the composition.

Prominent Artists: Key artists associated with the Impressionist movement include Claude Monet, Edouard Manet, Camille Pissarro, Pierre-Auguste Renoir, Alfred Sisley, Edgar Degas, and Henri de Toulouse-Lautrec. Each artist contributed to the movement with their unique style and interpretation of the principles.

In summary, Impressionism sought to capture the transient effects of light and color, encouraging artists to paint from direct observation, often outdoors, and to challenge traditional notions of color representation in art.